Ground level service rack for pole-mounted fixtures

ABSTRACT

An assembly for ground level installation and servicing of one or more pole-mounted light sources includes a support rack having guide sheaves which ride the pole in response to operation of a hoist cable and pulley arrangement. To slow the fall of the rack in the event of hoist cable failure during raising or lowering, the guide sheaves are urged against the pole by springs which remain in compression independently of hoist cable tension. The rack is latched at the pole top independently of the hoist cable and is releasable at ground level by actuation of a latch line. Light sources are mounted on the rack at a higher elevation than the guide sheaves to cause the sheaves, rather than the sources, to absorb substantially all impact if the rack falls.

United States Patent 1 [111 3,805,054 Wolf Apr. 16, 1974 GROUND LEVELSERVICE RACK FOR 1968. pp. 5 and 10.

POLE-MOUNTED FIXTURES [76] Inventor: John H. Wolf, 1710 22nd St., LakeCharles, La. 70601 [22] Filed: Dec. 9, 1970 [21] App]. No.: 96,540

[52] US. Cl 240/70, 240/64, 240/84, 248/320 [51] Int. Cl. F21! 21/38[58] Field of Search 240/63, 64, 67, 70, 84; 248/320, 408

[56] References Cited UNITED STATES PATENTS 3,670,159 6/1972 Millerbernd240/65 1,026,360 5/1912 Munson et a]. 248/322 2,618,454 11/1952Farrington 240/67 X 3,342,988 10/1967 Farrington 240/84 X FOREIGNPATENTS OR APPLICATIONS 1 10,405 5/1900 Germany 240/64 461,636 10/1968Switzerland 240/64 OTHER PUBLICATIONS Quality Outdoor Lighting BrochureHi-Mast Primary Examiner-Fred L. Braun Assistant Examiner-E. M. BeroAttorney, Agent, or FirmRose & Edell [5 7] ABSTRACT An assembly forground level installation and servicing of one or more pole-mountedlight sources includes a support rack having guide sheaves which ridethe pole in response to operation of a hoist cable and pulleyarrangement. To slow the fall of the rack in the event of hoist cablefailure during raising or lowering, the guide sheaves are urged againstthe pole by springs which remain in compression independently of hoistcable tension. The rack is latched at the pole top independently of thehoist cable and is releasable at ground level by actuation of a latchline. Light sources are mounted on the rack at a higher elevation thanthe guide sheaves to cause the sheaves, rather than the sources, toabsorb substantially all impact if the rack falls.

9 Claims, 8 Drawing Figures PATENTEUAFR 16 m V M305; 054

SHEET 1 [1F 3 Q '27 \NVENTDR JOHN H. LUDLF QTYDRNEYS PATENTEDAPR 16 1914SHEET 2 [IF 3 \QQENTDZ JOHN H. LUDLF Es Wm ATTD ENEYS PATENTED APR 18I974 SHEH3UF3 INVENTUR JOHN H- LUOLF Xfi ATTDEMEYS GROUND LEVEL SERVICERACK FOR POLE-MOUNTED FIXTURES BACKGROUND OF THE INVENTION The presentinvention relates to improvements in pole mounted electrical equipmentand more particularly to such fixtures which can be easily installed onstandard support poles and can be serviced at ground level with safe andsimple procedures.

Prior art pole-mounted lighting assemblies of the type which can beserviced at ground level are characteristically represented in SwissPat. No. 461,636 to Jean Rubeli. Briefly, Rubeli discloses a rack onwhich one or more lamps are mounted and which are raised or lowered on avertical support pole by a hoist cable and pulley arrangement. The rackis held in its operative position atop the pole by tension maintained inthe hoist cable. Contact between the rack and pole is ef fected viaguide rollers which are urged against the pole as long as there istension in the hoist cable. Should the hoist cable break, either withthe rack atop the pole or during raising or lowering of the rack, theentire rack falls freely to the ground, endangering passersby andmaintenance personnel. Moreover, Rubelis unit is constructed so that thelamp fixtures extend below the remainder of the rack and thereby absorbsubstantially all of the impact if the rack falls. Consequently theselamp fixtures, which are the most expensive parts of the assembly, arequite likely to be demolished if the rack falls. In addition,installation of Rubelis assembly requires considerable modification ofstandard support poles.

It is therefore an object of the present invention to provide a groundlevel service rack for pole-mounted lighting assemblies and similarelectrical equipment whereby the rack is safely latched in its operativeposition, independent of hoist cable tension, and whereby the entireassembly may be simply installed on standard support poles withoutmodification to the pole itself.

It is another object of the present invention to provide a ground levelservice rack of the type described where guide sheaves mounted on therack are urged against the pole at all times, independently of hoistcable tension, thereby slowing the fall of the rack in the event ofhoist cable failure during a raising or lowering procedure.

It is still another object of the present invention to provide a groundlevel service rack of the type described wherein a relativelyinexpensive portion of the rack is arranged to absorb most of the impactif the rack falls to the ground.

SUMMARY OF THE INVENTION The ground level service rack of the presentinvention includes a latching arrangement'to hold the rack in itsoperative position independently of hoist cable tension. In addition,the rack-mounted guide sheaves are continuously urged against thesupport pole by compressed springs to provide frictional engagementbetween the rack and pole and slow any possible fall of the rack. A setof guide sheaves is disposed below the remainder of the rack assembly sothat these sheaves receive most of the impact if the rack should fall.The support assembly for the rack is adapted to be mounted on a standardsupport pole slip-fitter arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS The above and still further objects,features and advantages of the present invention will become apparentupon consideration of the following detailed description of specificembodiments thereof, especially when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a view in elevation of the ground level service rack of thepresent invention and a support pole therefor, wherein raising, loweringand latching of the rack is illustrated diagrammatically;

FIG. 2 is a view in perspective of a fixed support assembly for the rackas positioned atop the support pole;

FIG. 3 is a sectional view along lines 33 of FIG. 2;

FIG. 4 is a view in perspective of the movable service rack illustratingthe manner in which the rack rides the support pole;

FIG. 5 is a view in perspective of the base of the support pole;

FIG. 6 is a plan view in elevation of the movable support rack latchedto the support assembly atop the support pole;

FIG. 7 is a side view in section taken along lines 7--7 of FIG. 6; and

FIG. 8 is a top view in section taken along lines 88 of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, a support polel of generally cylindrical configuration is arranged to receive a fixedsupport assembly 20 at its top and is slidably engaged at its peripheryby a movable rack assembly 50. As is described in detail below, rack 50is normally latched in its operative position by assembly 20 and isselectively raised or lowered along pole 1 from a location at the baseof the pole.

Referring now to the drawings, pole 1 includes a top section 2 ofreduced diameter extending upwardly from an annular shoulder 3. Section2 forms a standard slipfitter which is engaged by a hollow cylindricaltube 21 forming part of support assembly 20. Tube 21 rests on shoulder 3and is interiorly braced by slipfitter 2. A set screw 30 is threadedthrough tube 21 and abuts slipfitter 2 to lock assembly 20 in place. AU-shaped bracket 22 is welded or otherwise secured to the top of tube 21in inverted position to provide support for a hoist sheave and a latcharrangement to be described. Two smaller U-shaped brackets 23, 24 aresecured along their edges atop bracket 22 in spaced relation. A hoistsheave or pulley 25 is rotatably mounted between brackets 23, 24 bymeans of shaft 26 which is journaled in each of the brackets and fixedlysecured to the pulley. A peripheral track is provided in pulley 25 toaccommodate a hoist cable 27.

A latch assembly includes baseplate 28 in the form of an invertedU-shaped bracket supported atop brackets 23, 24. Opposite ends of thebaseplate are slotted at 29, 31 to receive respective verticallyextending latch members 32, 33 in the form of flat plates of steel orother suitable material. The latch members are pivotally mounted tobaseplate 28 in the region of slots 29, 31 by means of pivot pins 34disposed such that both latch members are pivotable in a common plane.

A cable 35 is secured to the upper end of each of latch members 32, 33and prevents these members from being separated at their upper ends by adistance significantly in excess of the distance between pivot pins 34.Coiled tension springs 36, 37 are provided to normally maintain latchmembers 32, 33, respectively, in vertical positions. Specifically,spring 36 extends horizontally between pipe 21 and latch member 32 at alocation below pivot pin 34. When latch member 32 is vertical spring 36is relaxed; however, any tendency of latch member 32 to pivot clockwise(as viewed in FIGS. 1, 2) is opposed by spring 36. A similar situationexists for latch member 33 which is opposed from pivotingcounter-clockwise by spring 37. The lower extremities of latch members32, 33 are configured as hooks arranged to engage rack assembly 50 inthe manner to be described.

A latch line 38 in the form of a cable is secured to cable 35 andextends down into pole 1 through suitably provided holes in baseplate 28and bracket 22. The lower extremity of latch line 38 is accessible atthe bottom of pole 1, and if pulled downwardly, serves to pivot latchmembers 32, 33. More specifically, when latch line 38 is so pulled,cable 35 pulls the upper ends of the latch members toward one another,thereby forcing the hooked lower ends of these members to swingoutwardly.

Four guide members 39, 41, 42 and 43, in the form of verticallyextending plates are edge welded to tube 21 and define guide spaces forthe guide sheaves of rack assembly 50 to be described below. The lowerportions of guide members 39, 41, 42, 43 extend below tube 21 along pole1 and are curved to permit the rack guide sheaves to be smoothly guidedinto position.

A support sheave 45 of nylon or similar material is pivotally mounted onthe outer surface of tube 21 proximate a slot 46 in the tube. A portionof support sheave 45 extends through slot 46 into tube 21. The purposeof sheave 45 is to support and carry a power cable 47 which extendsupwardly through the interior of pole 1 and out through slot 46 toprovide electrical power for rack 50.

Rack assembly 50, as best illustrated in FIGS. 4 and 6, comprises asquare or rectangular frame 51 formed by hollow tubing which serves as aconduit for electrical cable. A plurality of short tubes 52 extendupwardly from various locations on the frame and serve as slipfitterswhich support various lighting fixtures 53. The number and location ofslip-fitters 52 are determined by the lighting requirements of aparticular application.

Four hollow tubes 54 extend inwardly of frame 51 from the centers of thefour legs respectively, of the frame. Four additional hollow tubes 55telescope interiorly of tubes 54 and terminate at respective U brackets56. The latter pivotally support respective guide sheaves 57 which arecontoured to roll vertically along pole 1. A compression spring 58 isprovided for each set of telescoping tubes 54, 55 extending interiorlyof both tubes to urge sheave 57 against pole 1.

The four guide sheaves 57 are generally co-planar with frame 51. Thereare four additional guide sheaves 59 pivotally supported by respectiveU-brackets 61 below the frame. Brackets 61 are in turn supported byvertical beams 62 secured to respective tubes 55. Thus, since tubes 55and sheaves 57 are urged by compression springs 58 toward pole l, thelower set of guide sheaves 59 are similarly urged by the same springs.

A pair of eye bolts 63 are secured to and extend upwardly from frame 51at the centers of a pair of opposite frame legs. A hoist bridle 64, inthe form of a steel cable, is secured at its ends to bolts 63 and hassufficient slack to permit it to clear the main plane of frame 51 whenbridle 64 is lifted. Bridle 64 is secured to hoist cable 27 which, asdescribed below, is employed to raise and lower rack along pole 1.

A pair of U-bolts 65 have their legs secured to an opposite pair oftubes 54 at radial distances from pole l which are sufficient to permitbolts 65 to be engaged by the hooked lower ends of latch members 32, 33.In the manner to be described, engagement of these bolts by the latchmembers supports rack 50 in its operating position, independently oftension in hoist cable 27.

An electrical power connector 66 is secured to one of tubes 54 of frame51. Connector 66 mates with a plug 48 at one end of power cable 47,which rides up and over support sheave 45 into the interior of pole 1and terminates at its other end in electrical connector 49. A conduit 67carries electrical wires from connector 66 to the interior of frame 51.

. At the base of pole 1, as best illustrated in FIGS. 1 and 5, is anaccess opening 4 by which maintenance personnel can have ground levelaccess to hoist cable 27, power cable 47 and latch line 38. The base ofpole 1 is set rigidly in a cement block 5 into which eye bolts 6 and 7and conduit 8 are set. A shackle 9 mates at one end with eye bolt 6 andpivotally supports a sheave 11 for hoist cable 27. Cable 27 may beconnected to a winch (not illustrated) or the like by means of loop 27aexteriorly of access opening 4 for the purpose of raising or loweringrack assembly 50.

Latch line 38 is permanently tied or otherwise secured to eye bolt 7such that line 38 is taut when latch members 32, 33 are vertical. Adownward pull on latch line 38 tends to pivot the upper ends of thelatch members toward one another by forcing cable 35 in a downwarddirection.

The exposed end of conduit 8 terminates in a connector 12 which mateswith either connector 13 of a ser vice cable 14 or connector 49 of powercable 47. More particularly, when rack assembly 50 is in its operativeposition atop pole 1, power cable 47 extends to the base of pole 1permitting connectors 12 and 49 to be mated. When the rack is lowered,cable 49 is disconnected from connector 12 and electrical connections tothe cable are provided via service cable 14. For this purpose, the upperend of cable 14 terminates in con nector 15 which mates with connector49.

To illustrate the advantages of the present invention, assume rackassembly 50 is at ground level and is to be raised to its operativeposition atop pole 1. Hoist cable 27 is pulled, with sheaves 11 and 25re-directing the hoisting force, to raise rack 50 by means of bridle 64.As the rack is hoisted up the pole, compression springs 58 urge theeight guide sheaves 57, 59 against the pole. importantly, if cable 27were to snap during a hoisting operation, springs 58 remain incompression and continue to urge the eight guide sheaves 57, 59 againstpole 1. The fall of rack assembly 50 would therefore be considerablyslowed and danger to personnel on the ground would be minimized.Moreover, if the rack assembly were to fall, the lower set of guidesheaves 59 would absorb most of the impact and the possibility of damageto lamp fixtures 53 would be quite small.

When rack assembly 50 is hoisted to the top of pole l, U-bolts 65 comeinto contact with the bottom edges of latch members 32, 33. These edgesare sloped upwardly toward the pole so that upward pressure by theU-bolts against the sloped edges tends to pivot the lower ends of thelatch members outwardly against the tension in springs 36, 37. Hoistingof the rack is contin ued until bolts 65 rise above the sloped loweredges of the latch members at which point the latch members are pulledback into their vertical positions by springs 36, 37. Tension in hoistcable 27 is then released and bolts 65 settle into engagement with thehooked lower regions of latch members 32, 33. Rack assembly 50 istherefore supported in this, its operative position, by the latchmembers.

Proper rotational alignment of the rack at the top of pole l is assuredby virtue of sheave guides 39, 41, 42 and 43. Specifically, these guidesdefine four spaced regions about the periphery of the top of pole 1within which sheaves 59 fit. The flaring lower ends of the guides act todirect the hoisted sheaves into the spaced regions to assure properpositioning of the rack.

When the rack is in its operative position, power cable 47 extends tothe base of the pole and can be con nected to fixed connector 12.

If now it is desired to lower rack 50 for maintenance purposes, powercable connector 49 is disconnected from connector 12 and service cable14 is connected between these two connectors. Hoist cable 27 is placedin tension and the rack is raised slightly. Latch line 38 is then pulleddownward, pivoting the hooked lower ends of latch members 32, 33outwardly, U-bolts 65 having been raised sufficiently to permit them tobe cleared by the hooks' Tension on the hoist cable is then slowlyreleased to permit lowering of the rack assembly. Latch line tension isreleased after the rack is lowered sufficiently to permit U-bolts 65 toclear the hooked latch members. Lowering of rack assembly 50 iscontinued by means of hoist cable 27 until the rack assembly reachesground level. If hoist cable 27 should fail during rack lowering, fallof the rack is once again considerably slowed by guide sheaves 57, 59which are urged against the pole by springs 58.

While pole 1 illustrated herein is of cylindrical configuration, havingsubstantially constant diameter throughout its length, it is alsocontemplated that a generally conical support pole may be employed. Sucha support pole increases in diameter from top to bottom and therefore isengaged at its lower end with greater frictional force by thespring-biased guide sheaves 57, 59. Thus, a falling rack assembly on aconical support pole experiences increasing friction the further itfalls.

Important, also, is the fact that the assembly of the present inventionis readily adapted to mounting on standard support pole slip-fitterswithout the need for cutting, welding, drilling, tapping or othermodification. This feature has significant economic advantages sincestandard poles may be fitted with the arrangement of the presentinvention. In addition, since conduit 8 and bolts 6 and 7 are set incement block 5, no modification is required of the standard pole at itsbase for purposes of the present invention.

While I have described and illustrated specific embodiments of myinvention, it will be clear that variations of the details ofconstruction which are specifically illustrated and described may beresorted to without departing from the true spirit and scope of theinvention as defined in the appended claims.

I claim:

1. An electrical fixture assembly adapted to be mounted on a generallyvertical support pole, comprisa fixed mounting assembly secured to saidpole at a predetermined elevation;

a rack assembly positioned about said pole for slidable movement alongsaid pole, said rack assembly supporting at least one electric fixtureand including: a plurality of guide sheaves arranged to movably engagesaid pole, and a plurality of spring members for continuously urgingrespective ones of said guide sheaves against said pole; and

hoisting means secured to said fixed mounting assembly and including ahoist cable accessable at ground level and secured to said rackassembly, said hoisting means being provided for selectively raising andlowering said rack assembly along said pole;

wherein a portion of said rack assembly is disposed at 'a lower levelthan any electrical fixutres supported by said rack assembly, saidportion of said rack assembly acting as a shock absorber to preventdamage to said light fixture in the event said rack assembly falls tothe ground.

2. The combination according to claim 1 further comprising latch meansfor supporting said rack assembly at said predetermined elevation, saidlatch means including at least one pair of co-operating members arrangedfor mutual engagement when said rack assembly is at said'predeterminedelevation, and latch control means for selectively disengaging saidmembers to permit lowering of said rack assembly.

3. The combination according to claim 1 wherein said portion of saidrack assembly includes a plurality of said guide sheaves.

4. The combination according to claim 1 wherein said hoisting meanscomprises a hoist sheave secured to said fixed mounting assembly and abridle secured to said rack assembly, said hoist cable being secured atone end to said bridle, supported by said hoist sheave, and extending toground level interiorly of said pole.

5. The combination according to claim 4 wherein there is furtherprovided an electrical supply outlet at the base of said pole andinteriorly thereof, an electrical connector secured to said rackassembly for receiving electrical power and supplying same to saidelectrical fixtures, and a power cable for interconnecting saidelectrical supply outlet to said electrical connector when said rackassembly is at said predetermined elevation, said power cable extendinginteriorly of said pole between said supply outlet and at least saidpredetermined elevation.

6. The combination according to claim 5 wherein said electrical fixturesare lighting fixtures.

7. The combination according to claim 1 including latch means comprisinga pair of spring-biased hook members secured to said fixed mountingassembly, a pair of further members secured to said rack assembly andadapted to be engaged by respective ones of said hook members, and alatch line extending from said hook members to ground level interiorlyof said pole,

said latch line being arranged, when pulled, to disengage said hookmembers from said further members. 9. The combination according to claim1 wherein 8. The combination according to claim 1 wherein a said springmembers are compression springs, and plurality of said guide sheaves aredisposed below the wherein said predetermined elevation is the top ofsaid remainder of said rack assembly and particularly below pole. saidelectrical fixtures.

1. An electrical fixture assembly adapted to be mounted on a generallyvertical support pole, comprising: a fixed mounting assembly secured tosaid pole at a predetermined elevation; a rack assembly positioned aboutsaid pole for slidable movement along said pole, said rack assemblysupporting at least one electric fixture and including: a plurality ofguide sheaves arranged to movably engage said pole, and a plurality ofspring members for continuously urging respective ones of said guidesheaves against said pole; and hoisting means secured to said fixedmounting assembly and including a hoist cable accessable at ground leveland secured to said rack assembly, said hoisting means being providedfor selectively raising and lowering said rack assembly along said pole;wherein a portion of said rack assembly is disposed at a lower levelthan any electrical fixutres supported by said rack assembly, saidportion of said rack assembly acting as a shock absorber to preventdamage to said light fixture in the event said rack assembly falls tothe ground.
 2. The combination according to claim 1 further comprisinglatch means for supporting said rack assembly at said predeterminedelevation, said latch means including at least one pair of co-operatingmembers arranged for mutual engagement when said rack assembly is atsaid predetermined elevation, and latch control means for selectivelydis-engaging said members to permit lowering of said rack assembly. 3.The combination according to claim 1 wherein said portion of said rackassembly includes a plurality of said guide sheaves.
 4. The combinationaccording to claim 1 wherein said hoisting means comprisEs a hoistsheave secured to said fixed mounting assembly and a bridle secured tosaid rack assembly, said hoist cable being secured at one end to saidbridle, supported by said hoist sheave, and extending to ground levelinteriorly of said pole.
 5. The combination according to claim 4 whereinthere is further provided an electrical supply outlet at the base ofsaid pole and interiorly thereof, an electrical connector secured tosaid rack assembly for receiving electrical power and supplying same tosaid electrical fixtures, and a power cable for interconnecting saidelectrical supply outlet to said electrical connector when said rackassembly is at said predetermined elevation, said power cable extendinginteriorly of said pole between said supply outlet and at least saidpredetermined elevation.
 6. The combination according to claim 5 whereinsaid electrical fixtures are lighting fixtures.
 7. The combinationaccording to claim 1 including latch means comprising a pair ofspring-biased hook members secured to said fixed mounting assembly, apair of further members secured to said rack assembly and adapted to beengaged by respective ones of said hook members, and a latch lineextending from said hook members to ground level interiorly of saidpole, said latch line being arranged, when pulled, to disengage saidhook members from said further members.
 8. The combination according toclaim 1 wherein a plurality of said guide sheaves are disposed below theremainder of said rack assembly and particularly below said electricalfixtures.
 9. The combination according to claim 1 wherein said springmembers are compression springs, and wherein said predeterminedelevation is the top of said pole.